Master Cylinder Overhaul. Chevrolet PJJ 2000

For 1990-2009 cars

### Disassembly Procedure

1. Remove the master cylinder from the vehicle. Refer to Master Cylinder Replacement.
2. Empty the fluid from the reservoir of the master cylinder.

Notice: Do not clamp on the master cylinder body. Doing so may damage the master cylinder.

3. Mount the master cylinder in a vise.
4. Clean the area around the master cylinder reservoir cover.
5. Remove the master cylinder reservoir cover (1).
6. Remove the master cylinder reservoir cover diaphragm (2).
7. Inspect the master cylinder cover and the diaphragm for the following conditions. Replace the parts as necessary:

• | Cuts

• | Cracks

• | Nicks

• | Deformation

8. Remove the low brake fluid level switch. Refer to Brake Fluid Level Indicator Switch Replacement .
9. Remove the piston retainer (13) while depressing the primary piston (12). Use care not to damage the primary piston (12), the master cylinder bore, or the piston retainer groove.
10. Remove the primary piston (12). Apply low pressure, non-lubricated, compressed air into the upper outlet port at the blind end of the bore with all of the other outlet ports plugged.
11. Remove the secondary piston (10). Apply low pressure, non-lubricated, compressed air into the upper outlet port at the blind end of the bore with all other outlet ports plugged.
12. Remove the secondary piston spring (7) and the spring retainer (8). Apply low pressure, non-lubricated, compressed air into the upper outlet port at the blind end of the bore with all of the other outlet ports plugged.
13. Remove the secondary seal (11).
14. Remove the primary seal (9).
15. Remove the spring retainer from the secondary piston.

• | Clean all parts in clean, denatured alcohol.

• | Dry the parts with non-lubricated, compressed air.

• | Do not use an abrasive on the bore.

16. Inspect the master cylinder bore for scoring or corrosion. Replace the master cylinder if damage is found.

### Assembly Procedure

1. Lubricate all rubber parts with clean brake fluid in order to ease assembly.
2. Install the secondary seal (9) onto the secondary piston (10).
3. Install the primary seal (11) onto the primary piston (12).
4. Install the spring retainer (8) onto the secondary piston (10).
5. Install the secondary piston spring (7) into the cylinder bore.
6. Install the secondary piston assembly into the cylinder bore.
7. Install the primary piston (12) into the cylinder bore.
8. Depress the primary piston (12) in order to install the piston retainer (13).
9. Install the low brake fluid level switch. Refer to Brake Fluid Level Indicator Switch Replacement .
10. Install the master cylinder reservoir diaphragm (2) into the reservoir cover (1).
11. Install the master cylinder reservoir cover (1) onto the master cylinder reservoir (4).
12. Install the master cylinder. Refer to Master Cylinder Replacement.